Steam-engine.



No. 642,492. Patented l an. 30, I900. M. R. ossms. STEAM ENGINE.

(Application filed May 24, 1899.) No Mod eI.)

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'NITED STATES PATE T OFFICE.

MOSES RILEY ROBBINS, OF VICTORIA, BRITISH COIJUMBIA, CANADA, AS- SIGNO-R OF ONE-HALF TO ARTHUR E. MALLETT, OF SAME PLACE.

STEAM-ENGINE.

SPECIFICATION forming part of Letters Patent No. 642,492, dated January 30, 1900.

' Application filed May 24, 1399. $erialNo.718,042. (No model.)

To all whom it may concern:

Be it known that I, MOSES RILEY ROBBINS, of Victoria, in the Province of British Columbia and Dominion of Canada, have invented a new and Improved Steam-Engine, of which the following is a full, clear, and exact description.

The purpose of this invention is to provide a superior arrangement by which the usual slide-valve of a steam-engine cylinder may be dispensed with and in which the piston will be fitted with valve mechanism serving alternately to admit the steam to each side of the piston, the piston also serving to control the exhaust-valve by direct contact of the piston with such valve.

This specification is the disclosure of one form of my invention, while the claims define the actual scope thereof.

Reference is to be had to the accompanying drawings, forming a part of this specification, in which similar characters of reference indicate corresponding parts in all the views.

Figure 1 is a section taken longitudinally through the cylinder and coacting parts. Fig. 2 is a section on the line 2 2 of Fig. 1, and Fig. 3 is a fragmentary bottom plan showing one of the exhaust-valves.

The cylinder 4 has near each end an exhaust-port 5, each port having an inwardlyextending offset or slot 6. The ports 5 are commanded by slide-valves 7, each having a stem 8, the stems being located in the transverse centers of the valves, so that when the valves are in open position the stems will move into corresponding slots or offsets 6, as shown at the right of Fig. 1. Connected with the stems 8 is a rod 9, which passes to one end of the cylinder and is coupled to a handlever 10, by means of which lever the engine may be reversed and stopped, as will be fully described hereinafter.

The head 11 of the engine has a packinggland 12 therein, through which is passed a piston-rod 14. This rod is joined to a piston 15, which may be, if desired, constructed in sections bolted together, as shown. The other head 16 of the cylinder has a pipe 17 communicating therewith, in which slides a pipe 18, such pipe serving to lead the steam to the interior of the piston. The pipe 18' communicates with an approximately triangular chamber 19, which is formed in the piston and which has at its central or upper portion an elbow or bend serving to direct the steam radially with respect to the piston and in a line at right angles to the pipe 18. Working snugly in the chamber 19 is a cut-off plate or valve 20, which has a doublebevel upper edge 21 located just beneath the' elbow at the upper portion of the chamber 19. The cutoff valve 20 has a pin 22 secured thereto and extending transversely through it, the pin sliding in the faces of the piston and having expansive balance-springs 23 respectively encircling its ends and serving normally to hold the cut-oif in the center of the chamber, the springs 23 being of such tension that the pressure of steam may overcome them in either direction. The cut-off valve 20 moves from face to face of the piston to command the steam feed-ports 24, which are two in number and formed in the respective faces of the piston to communicate with the chamber 19.

In the operation of the engine the lever 10 is thrown to properly adjust the slide-valve 7, so that the desired port 5 will be opened.

By means of the arrangement of slide-valves it is possible to start the engine in either direction, as will be understood upon examination of the drawings. The steam entering through the pipe 18 passes into the chamber 19 and through the ports 24. The steam at the side of the piston at which side the slidevalve thereof is opened will pass out of the cylinder to the exhaust without actuating the piston; but the steam at the other side will the cut-ofi valve 20 to push the same against one face of the cylinder and close the port 24 thereof. Therefore, assuming that the parts are in the position shown in Fig. 1, the steam passing through the left-hand port 24 will expand, since the left-hand slide-valve is closed, and the piston will be pushed to the right. This will also throw the cut-off valve to the position shown in Fig. 1, thus closing the right-hand port 24. The piston continues this rightward movement until it strikes the righthand valve 7 and throws the same to the right, thus closing the adjacent port 5 and simultaneously opening the left-hand port 5. Now

expand in the cylinder and also will act on the steam at the left of the piston will exhaust itself and the steam at the right will expand to drive the piston to the left and simultaneously to shift the cut-off valve 20 so as to close the left-hand port 24. Thus the engine operates continuously until the operation is reversed or arrested by manipulation of the hand-lever 10. The engine may be stopped by throwing the lever to partly open both of the exhaust-ports 5, so that the steam will escape at both sides of the piston. The double bevel at the upper end of the cut-0E valve serves to permit the steam to expandat a portion of each side of the cut-off valve, thus facilitating the shifting of the valve as the piston reaches the ends of its strokes.

Having thus described my invention, I claim as new and desire to secure by Letters Patent- 1. The combination of a cylinder having an exhaust-port in each end thereof, a slide-valve commanding each exhaust-port, a connection between the slide-valves to operate the same in unison, a piston working in the cylinder and having a chamber therein, a pipe communicating with the chamber of the piston and sliding in one head of the cylinder, the piston having a port in each face, the ports communicating with the chamber, a cut-off valve movable in the chamber of the piston to command the ports thereof, a pin attached to the valves and sliding in the face-walls of the piston, and springs engaging the pin to balance the cut-off valve.

2. The combination of a cylinder having an exhaust-port adjacent to each end thereof, valves commanding each exhaust-port, a connection between the valves to operate the same in unison, a piston working in the cylinder and having a chamber in each exhaustport therein and wall of the piston, said ports communicating with the chamber, a steampipe moving with the piston and leading the steam to the chamber thereof, and a cut-off Valve working in the-chamber and commanding the ports thereof.

3. The combination of a cylinder, having an exhaust-port adjacent to each end thereof, valves controlling the exhaust-port, a piston working in the cylinder and actuating the valves, the piston having a chamber therein, a pipe moving with the piston and feeding the steam to the chamber thereof, the piston also having portsin its face-walls, the ports communicating with the chamber of the piston, and a cut-0E valve working in the chamher and commanding the ports of the piston.

4. The combination of a cylinder having ex haust-ports, valves commanding the same, a piston Working in the cylinder and actuating the valves, the piston having a steam-chant her and ports communicating therewith, piston, and a cut-01f valve Working in the means for leading the steam to the steamchamber of the said chamber and commanding the ports of the piston.

5. The combination of a cylinder having an exhaust-port adjacent to each end thereof, valves commanding the exhaust-ports, a connection between the valves to work the same in unison, a piston working in the cylinder and having a chamber to which the steam is fed, the piston also having ports in each face thereof, the ports communicating with the chamber, and means commanding said ports to alternately open and close the same.

MOSES RILEY ROBBINS.

Witnesses:

GEORGE CARTER, JAMES MALLETT. 

